The Black Hole Next Door

A nearby object mirrors events across the cosmos

Astronomers have been pondering the riddle of the quasars for more than 30 years, wondering what prodigious energy source could possibly make these starlike objects visible from halfway across the universe. The leading theory: a quasar is gas falling into a gigantic black hole. As the gas is compressed, it heats up to millions of degrees, glowing brightly enough to outshine an entire galaxy; occasionally, jets of hot gas spray out, like juice squirting from a squeezed orange.

Since quasars lie billions of light-years from earth, astrophysicists thought they might never prove the theory. But radio astronomers report in the current...